Compare the work you have promised with the recurring revenue it will bring. Start with a completed job sheet, supplier quotes and a crew schedule. Each example below uses hypothetical values you can replace.
Which calculator should you use?
| Tool | What it answers | What to check |
|---|---|---|
| Retainer Delivery Hours Available | Set a delivery-hour envelope for a recurring client agreement. | A negative answer means other costs already exceed the chosen cost envelope. Fixed overhead is not included unless entered. |
| Service Plan Contribution | Check contribution from a recurring service package. | Treat uncertain upsells separately. First test whether the committed included service covers its own costs. |
These tools answer different questions and may use different units. Choose the tool that measures what you need; a larger result does not necessarily mean a better outcome.
Retainer Delivery Hours Available
Set a delivery-hour envelope for a recurring client agreement.
Available hours = (retainer × (1 − margin) − other delivery costs) / hourly cost
Show example inputs and result
| Monthly retainer fee | 3,000 |
|---|---|
| Non-labour monthly delivery cost | 300 |
| Target contribution margin | 40 % |
| Loaded delivery hourly cost | 45 |
Result: 33.3333 hours per month.
A negative answer means other costs already exceed the chosen cost envelope. Fixed overhead is not included unless entered.
Open retainer delivery hours availableService Plan Contribution
Check contribution from a recurring service package.
Annual contribution = plan fee − visits × visit cost − admin cost
Show example inputs and result
| Annual plan price | 360 |
|---|---|
| Included visits per year | 2 |
| Variable cost per included visit | 90 |
| Annual member admin cost | 20 |
Result: 160 per member per year.
Treat uncertain upsells separately. First test whether the committed included service covers its own costs.
Open service plan contributionUse the results in your plan
For a plumbing service business, review fittings, access time, and travel across the complete workflow. Use one consistent period and delivery unit: a service visit. Compare the assumptions with recorded outcomes after delivery, then update the estimate.
Explore all relevant plumbing service calculators